The ceaseless pursuit of improvement in performance of electronic devices with simultaneous reductions in weight and volume has sought improvements in efficient heat sink designs for ever-increasing dissipative waste heat densities. Current and near future high-performance commercial/defense electronic devices require heat fluxes on the order of 100 W/cm2 to be dissipated. As the reliability and life span of electronics are both strongly affected by temperature, it is necessary to develop highly efficient cooling techniques to reduce the maintenance costs and increase the service life of high-power-density electronic devices.
Two-phase micro-channel heat sinks are an attractive solution for removing waste heat from high-power-density devices, as described for example in “Thermal Design Methodology for Low Flow Rate Single-Phase and Two-Phase Micro-Channel Heat Sinks,” by Scott Lee and Weilin Qu, published in IEEE Transactions on Components and Packaging Technologies, December 2007. Two-phase micro-channel heat sinks feature micro-size parallel channels as coolant flow passages for flow boiling of liquid coolant. Key merits include low thermal resistance to heat dissipation, large surface-area-to-volume ratio, small heat sink weight and volume, small liquid coolant inventory and flow rate requirement, and relatively uniform temperature distribution along the stream-wise direction. However, one practical concern that hinders the implementation of this powerful cooling scheme is the temperature and pressure oscillation due to flow instability. It would be desirable to provide an improved design which can prevent severe flow instability and therefore ensure safe operation and predictable cooling performance.